refractive index

American  

noun

Optics.

1. index of refraction.

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refractive index British  

noun

1.  ν.   μ.  physics a measure of the extent to which radiation is refracted on passing through the interface between two media. It is the ratio of the sine of the angle of incidence to the sine of the angle of refraction, which can be shown to be equal to the ratio of the phase speed in the first medium to that in the second. In the case of electromagnetic radiation, esp light, it is usual to give values of the absolute refractive index of a medium, that is for radiation entering the medium from free space

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Etymology

Origin of refractive index

First recorded in 1830–40

Example Sentences

See Examples For:

refractive index

This effect, known as photorefractivity, occurs when exposure to light alters the refractive index.

From Science Daily ● Apr. 21, 2026

A key concept behind this discovery is the refractive index, which describes how much a material bends or slows light.

From Science Daily ● Apr. 21, 2026

The large change in refractive index allows the formation of extremely fine patterns that remain embedded in the transparent material.

From Science Daily ● Apr. 21, 2026

The key difference in this new approach is the use of molybdenum diselenide, which has a much higher refractive index.

From Science Daily ● Apr. 5, 2026

Lack of optical homogeneity due to varying refractive index is likely to be partially responsible.

From Visual Illusions Their Causes, Characteristics and Applications by Luckiesh, Matthew